Like Flicking On a Switch
by karmascars
Summary: S3. Sam wants Dean any way he can get him, no matter if Dean's driving or not...


They're two miles out from the Daytona Speedway, hurtling north, when Dean glances over and sees a smirk toying across Sam's face. His own lewd grin spreads to match when he realizes Sam isn't looking at him, per se - more like down at his zipper. Dean's dick twitches harsh against rough denim, and he bites back an unmanly wince. Hell of a day to go commando.

"Somethin' on your mind, Sammy?" Dean's voice comes out even, steady; this is good. No evidence yet as to just how Sam's attention affects him. It's some kind of short in his wiring, he's sure - and even surer he doesn't give a shit.

Sam's eyes flick up to meet his, hazel darkening over that smirk. "Highway sure is flat. Level. Pretty smooth, too," he remarks in an innocent tone, completely incongruous.

Dean quirks an eyebrow at him. _Huh?_

His brother just chuckles, a dark little thing that almost doesn't suit him, and says, "Wanna test the alignment?" His eyes flicker down, back up.

_Ohhh_. Dean's jeans grow suddenly tighter. Damn kid, chubbin' him up at a time like this, and they just did laundry. That shit's constricting. He's got half a mind to find the nearest rest stop, bend Sam over one of those nasty public sinks, and show him just how _they_ align.

However, any challenge put to his Baby's condition must be met. "Alignment's fine," he grunts, resisting the urge to adjust himself or meet what he knows is his brother's entirely too amused expression. Instead, he focuses intently out the front. He can see for miles, nothing but asphalt, palm and oak. And cheesy billboards.

He likes those divided Ron Jon ones the best. When they drive through, he very privately pretends he's a shark that just bit the board in half.

Sam's laugh at Dean's defense is brighter, suits him better. "We haven't tested it on a road like this before," he says. "You hate the interstate."

"And it's your fault we're even on it," Dean complains on automatic. "Faster, my sweet ass." Still, he slides forward a little, can't help himself, cants his hips and slouches in an obvious invitation. Out of the corner of his eye, he catches the pink flash of Sam's tongue wetting dry lips.

"Maybe later," he thinks he hears the kid murmur, and Dean clenches in all kinds of places at that.

This spontaneous hunger for his cock shouldn't come as a surprise, but he's still bowled over by a blaze of lust whenever Sam gets like this. It's happened more and more often lately, a sudden, striking desire - just yesterday Sam met him in a diner bathroom, blew him sloppy up against a stall door and left him there. When Dean managed to totter back out to the booth, Sam was calmly finishing his leafy greens as though he hadn't just sucked his brother's brain out through his dick.

Revenge was had that night, a spontaneous dirty fuck in the back-alley of a bar. Almost getting caught by a trio of lit rednecks was worth Sam's wanton cries.

Dean thinks he might even know why Sam keeps pouncing, more and more frequently: after all, he only has two months left. He doesn't let himself dwell in regret, though, that they started this whole thing kind of late. That'd be a waste of energy better spent elsewhere. He just sends another ironic thanks to the bizarrely galvanizing effects of that Croatoan scare, and wriggles in his seat.

At the creak of leather, his brother laughs at him. "Ants in your pants?" he asks between snorts.

Dean rolls his eyes to disguise the way he tracks over Sammy's dimples, and traces the usual constellation of random moles across his face. The curly hair covering his brother's forehead, shading his eyes, makes Dean smile before he could help it. Damn, has he always been this far gone?

"What?" Sam demands, with a hint of customary dissatisfaction skewing his features.

Dean snorts. "What, nothing." _You're beautiful, kid_. "You gonna do something about this?" He gestures to his crotch, his cock at half mast and swelling further the longer Sam regards him. Dean can feel it making an outline there in his jeans, the frenulum ridge clearly defined. He's wet already, ticklish drips. The whole thing kinda aches.

Sammy loves to lick along that edge, Dean remembers with a shudder, his brother's clever tongue slick and wet through the slit, gathering beads of precome like they're candy. A little noise punches out of Dean, much to Sam's delight.

"Yeah," Sam says, "hell yeah," and then he's scooting, leaning, long fingers dancing over the bulge. A palm grinds down, sudden fierce friction. Dean hisses, grips the wheel a little tighter. His foot slams down to find the accelerator already on the floor. Gotta ease off, take her back down to ninety. Last thing he wants is highway patrol gettin' an unexpected eyeful - not because he gives even one fuck what they think, he just _ohhhh_

That train of thought derails completely.

"Shit, Sam," he growls, hips rolling up of their own accord to meet his brother's merciless hand. Dean bites his lip. They do it again.

"Yeah," Sam says again, slower, popping the button on Dean's jeans like he's getting paid for this. Each tooth of the zipper feels seismic against Dean's sensitive flesh, and he whines, can't help it. The temperature in the car has shot up about fifteen degrees, the already too-hot Florida spring becoming a preview of summer in Hell.

Sweat prickles over Dean's collar. "Sammy," he breathes, no aim to it, just his brother's name escaping.

"Hmm," Sam hums agreeably, freeing Dean's cock from his jeans and running loosely wrapped fingers up, and down the length. Feather-light touches. He sinks lower, intent on his prize, the heat of him compounding the rising fire his fingers are stoking. Dean fights to keep his head from flopping back.

"Sammm," he moans, eyelids suddenly heavy. He blinks, forces them back open. _Gotta watch the road, gotta focus -_

"I got you, Dean," Sam says, the words ghosting off Dean's skin. Dean shivers, his brother echoes, murmuring, "I got you..."

His arm across Dean's thighs, his hand around Dean's shaft, Sam brings wet lips to bear on the swollen head. Dean can't contain his explosive curse, every muscle seizing up. Something about this situation, sandwiched between Sam and his baby, turns his crank like nothing else. The car rumbles up beneath his thighs, and Sam suckles down over the head of his cock - not drawing him any deeper, the fuckin' tease. Dean strains against his brother's restraining arm.

"Sammy, man, c'mon," he gasps, wishing he had a free hand to guide Sam's head further down. This teasing is killing him. Both hands on the wheel, though, or they'll both die before it's time, perfect alignment be damned. "Ah, _shit_ -"

Sam seals his lips around and laughs, the bastard, sending tiny vibrations down that meet the engine's larger ones rattling up and through - Dean moans, already so loud, and then again with increasing volume as Sam slides down, ever so slowly, sealing him within tight, wet heat.

One bump on the road, and he could choke. Dean's never had to try so hard to focus in his life. Every ounce of him wants to thrust up, fall back, surrender to the swamping warmth, the prickling under his skin, but he can't. He can't even chase Sam's receding sin of a mouth when he draws back up. Nonsense falls from his lips, blasphemy and swears.

Swirl of the tongue around the head, and Dean gasps Sam's name, more air than sound.

He feels Sam hollow his cheeks then, once again sucking Dean's brain out through his dick as he plunges back down, swirl of the tongue and suck, over and over again. Dean is moaning steadily, sweating with the effort of _eyes on the road, hands on the wheel, fuck_, he's shaking. Thank whoever designed this road to be so fucking straight. Any curves have been great wide ones, requiring little effort. Any effort Dean is expending now is all to not just fuck Sam's mouth.

His brother pulls off with a pop and Dean wheezes, sucking in great gulps of air he'd forgotten he needed. _"Shit_," he gusts on an exhale, "Sam -"

Sam just grins. "Not done with you yet," he says, reaching for his water bottle. Dean makes a noise of both need and discomfort, the humid air of the cab hitting his dick like it's an Arctic current. After the bliss of Sam's mouth, anything else is purely torture. How does he manage to forget this every time?

Before Dean can untangle the mess of his brain, Sam's pouncing on him again, sucking him down with a ferocity that startles his curse into a squeak he will always deny. Sam laughs around him, and Dean grinds his ass into the seat at how that feels - his balls, trapped between his legs and all kinds of things, tighten and pull up. His whole body feels too hot, stretched thin between sanity and whatever Sam is doing with the swallowing, and lightly grazing teeth -

Dean is talking, babbling really. "Sam, I gotta - I gotta pull over -"

"Mmm, no," Sam growls, breath hot and heavy over Dean's skin. "I wanna see you lose it just like this."

Dean bites his lip on a whimper, hands white-knuckled on the steering wheel. "You itchin' to die?"

"Not gonna die," Sam says matter-of-factly, with a completely unfair lick up Dean's shaft that has him gasping, twitching. "You got this."

"I -" Dean can barely hear himself over the blood rushing in his ears. "I got nothin', Sam, _Jesus_ -"

_"You got this_," he feels more than he hears whispered over his dick, and Sam swoops back down to consume him.

Oh, fucking hell, this kid. Dean can't hold back his noises _and_ drive, so the car fills with wanton keening, the sound of utterly lost control. "Fuck, Sammy," he bites out, hips snapping up against Sam's arm. He's slouching so low his arm is extended all wonky as he fights to keep Baby in their lane. The world around them darkens, the sun meeting the horizon, but Dean is burning in his seat like it's still midday.

Sam does something glorious back in his throat that rolls down Dean's dick and up his spine. "Oh, fuck it," Dean spits out, wrenching the wheel. There's a rest stop half a mile ahead. He can feel Sam's smile around him, those long fingers tightening on his leg. "You're gonna get it, baby boy," he snarls, slamming them off of the freeway and into the exit lane at something like 105 mph.

The tires squeal when he brakes, surely leaving tracks of rubber behind them, but Dean is too occupied with throwing the car into park much too quickly and manhandling Sam upright. "Into the back," he bites out, tucking himself so he can follow the roll and tumble of his brother through the confining space.

He's wrenching Sam's jeans off his ass, and Sam is laughing.

"You think this is fucking funny?" Incredulous, Dean thrusts two fingers at Sam's swollen lips. "Suck."

"You know there's lube in the - _mmph_," Sam says, then moans, tongue skittering over Dean's fingers, getting them nice and wet.

"You love it," Dean counters roughly, circling Sam's pretty hole with his other thumb. His brother grunts, tilts his hips back for more. Something that might have been "_Fuck, Dean_" escapes around Dean's fingers.

He knows for a fact that Sam opened himself extensively in the shower that morning - he may have gotten off listening - so he's not worried about hurting him when he tears those fingers from his brother's mouth and slides one in his ass to the hilt. Sam's moan tells him it's fine, more than fine, and Dean works the finger around, feeling residual lube even now. "You like that?" he pants, breathless, pulling the finger out slowly and wriggling back in with two.

Sam groans at the intrusion, fucking back to meet it. "Fuck, you know I do," he says, and moans again, and the sound grabs Dean by the dick and pulls.

He grabs Sam's hip, slides his fingers free and licks his palm. "So do I," he sighs, lost, and positions himself at his brother's entrance.

Before he can push inside, Sam jerks back and takes the whole head in with a needy yelp. His hips work, he's rearing up on his knees as much as the space will allow, taking Dean inch by solid inch. It's all Dean can do to hang on, and moan in surprise when Sam seats himself with a drawn-out groan.

They pant together, the only sound for a moment, save Dean's thundering heartbeat. He's sure his brother can hear it. Hell, he can feel Sam's, in his fingertips, in his dick, rattling right along with him off this cliff.

Then, Sam whispers, breaks the spell and casts another: _"Move_."

Dean moves, shoves Sam's shoulder forward and down, and holds him there as he sets his knees, one foot awkwardly propped against the floorboard. The first jerk of his hips has Sam keening, canting back, and each subsequent slap of skin earns Dean a delicious noise and sweet clench around him. Fuck, Sam is always so tight. Dean tells him so, dark molasses and whiskey in his voice, and Sam backs up on him, sobbing, "God, Dean, so good -"

"Yeah," Dean tells him, "all for you," and fucks him that much harder.

The air in the car is stifling, each breath rasping in Dean's lungs, but he was never going to last long. Sam's too good, too tight, too goddamn irresistible for Dean to have any hope of holding off. His thrusts become erratic, and Sam senses it, start babbling, a steady shrieking litany of _Dean_ and _fuck_ and _come in my ass, c'mon, fill me up_ -

Dean loses it, he loses it hard, clutching Sam's hips to bruise and pumping in deep. He can't see, doesn't need to, bends over his brother's back and presses his mouth to the sweat-soaking shirts, imagines those times when they do this in nothing but skin. "Sam," he shakes out, lips numb, all-over prickly. "Sam..."

Sam's got a hand underneath them; Dean can feel him working himself furiously. The clenching of him around Dean's softening dick is some kind of torture, but Dean doesn't pull out yet. He grinds his hips forward, keeping his come pumped up inside, and reaches around beneath.

He finds frantic fingers and hard-swollen flesh, and Sam hisses when he takes over.

"Fuck, Dean, so fucking close -"

Dean drapes himself over Sam's back, purrs, "C'mon, Sammy, give it up."

A wretched cry. Hot slick spills over their fingers, and Sam shakes like he's shaking apart. Dean hums his approval, wringing his brother dry, squelching until Sam whimpers and tries to throw him off.

They separate, laughing raggedly, sprawling boneless on the soiled leather. Dean makes sure Sam sees him licking come off of his fingers.

Windows are cracked as quickly as the two of them can fumble for the cranks, and a welcome breeze begins to filter through. Dean plonks his head back against the glass, grateful for the zephyr licking through his sweaty hair. He can't imagine how Sam must feel. Would it help to wring him like a mop? Dean lets out a lazy, drunken laugh at that, and Sam eyes him, but is apparently too tired to even call him on it. Score.

Gradually, Dean becomes aware of movement. Then, abruptly, he panics. People, there are _people_ using this rest stop, cars _everywhere_, a mini van parked just three spaces away. It's nearing dark, but the place is fairly bustling. Children play some kind of screaming game in the lit concrete vicinity of the public restrooms.

The brothers meet each other's eyes in dawning horror. Quickly, Sam glances around, shaking fingers fumbling to pull up his waistband. "D'you think -" he begins, but bites his lip on the rest of it. Dean, tucking his own sensitive flesh away, ducks his head to peer out the front windows, the windshield.

He blinks. No one's raising an alarm, or even looking in their direction. He can't quite tell, but the driver of the mini van might be asleep. "No one noticed a thing," he says low, disbelieving.

Sam just looks at him, flatly incredulous.

They start to laugh at the same exact instant, and it's awhile before they stop. When the giggles peter out, Sam's gazing at Dean with a fondness that makes him uncomfortable. He clears his throat.

"You wanna stop somewhere for the night, or keep going?"

Just like that, Sam's gaze floods with heat. _Insatiable freak_, Dean can't help thinking, raising an eyebrow. _Oh?_

His brother shoots him a tired, half-smirk and says, "Wherever is fine by me."

_* fin_


End file.
